package de.metas.util;

import java.util.stream.Stream;

/*
 * #%L
 * de.metas.util
 * %%
 * Copyright (C) 2019 metas GmbH
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-2.0.html>.
 * #L%
 */

public class StreamUtils
{
	@SafeVarargs
	public static <T> Stream<T> concat(final Stream<T>... streams)
	{
		if (streams.length == 0)
		{
			return Stream.empty();
		}
		else if (streams.length == 1)
		{
			return streams[0];
		}
		else if (streams.length == 2)
		{
			return Stream.concat(streams[0], streams[1]);
		}
		else
		{
			Stream<T> result = streams[0];
			for (int i = 1; i < streams.length; i++)
			{
				result = Stream.concat(result, streams[i]);
			}
			return result;
		}
	}
}
